The function of the uncinate fasciculus is not known, though it is traditionally considered to be part of the limbic system.[2]

Diffusion tensor imaging, a reconstruction model available from a diffusion MRI scan, shows a greater fractional anisotropy on the left side than on the right. The difference in this measure of anisotropy has been linked to the left hemispheric specialization for language.[4] However, the use of electrical brain stimulation upon it fails to disrupt language, suggesting it might not be involved in language, though it is possible that this disruption failed to happen because it was functionally compensated by alternative pathways.[5]

The capacity for autonoetic self-awareness that is re-experiencing previous events as part of one's past as a continuous entity across time has been linked to the right uncinate fasciculus[6] as has proficiency in auditory-verbal memory and declarative memory to the integrity of the left uncinate fasciculus.[7]

The uncinate fasciculus has the longest period of development in terms of fractional anisotropy as it alone amongst the major white fibre tracks continues to develop beyond the age of 30.[8]

It seems to be developmentally vulnerable. In 12-year-old males that were preterm, abnormalities measured by fractional anisotropy in the left anterior uncinate correlated with verbal IQ, full-scale IQ, and Peabody Picture Vocabulary Test-Revised scores.[9] In 10-year-old children who have suffered socioemotional deprivation, the left uncinate fasciculus shows reduced fractional anisotropy compared to that in other children, and this might underlie their cognitive, socioemotional, and behavioral difficulties.[10]

In 2009 it was implicated in psychopathy—individuals with a high score in the Psychopathy Checklist and an associated history of violent behavior appeared to have abnormalities in it.[20]

Phineas Gage ( a railroad worker who had an iron bar go through his left frontal lobe)[21] had damage done to his uncinate fasciculus. After the accident, his intellect was untouched, but his personality transformed. He lost all sense of morality and concern for others.